The invention relates to goods-handling doors.
The term “goods-handling doors” is used to designate doors installed in warehouses, factories, stores, sheds, etc. to make communication possible between different volumes or with the outside, and to provide temperature and noise insulation between said volumes or relative to the outside. Such a door makes it possible to close and to open an opening formed in a wall, and it must be capable of being opened and closed rapidly in order to limit the time during which the insulation is no longer provided. It is common for the door to include a panel mounted to move up and down between two uprights. It is also common for the door to be provided with a curtain that can be rolled or folded up at the top of the opening or on either one of the sides of the opening, the curtain generally being a flexible sheet or being made up of hinged panels. A rotary shaft is disposed, for example above the opening, to roll up the curtain, or else straps are provided to raise the curtain. The curtain is generally reinforced by at least one rigid bar whose ends slide with the edges of the curtain in vertical (or optionally horizontal) slideways.
One type of goods-handling door includes two brackets disposed on either side of the door at the top thereof.
An example of such a door is described in EP-0 717 807. That example is shown in accompanying FIG. 1, and it is described below with reference thereto. An opening 2 is formed in a wall 1. The door includes a flexible curtain 3 that can be rolled up around a shaft 4 disposed above the opening. Respective brackets are fixed on either side of the top of the opening. In that example, each bracket 10 is L-shaped (10G on the left and 10D on the right), comprising a first branch fixed against the wall and a second branch perpendicular to the first branch. The second branch 102G of the left-hand bracket 10G carries a first seat 103 for a bearing, and the second branch 102D of the right-hand bracket 10D carries a second seat for a bearing. The shaft 4 is carried by the two seats. The left-hand bracket carries a seat only, whereas the other bracket also carries all of the electrical control and mechanical drive members for the shaft: an electric motor 104, generally with incorporated brake and gearing, an end-of-stroke stop 105, and various relays and other electrical members 106. The curtain shown can be rolled up directly onto the shaft 4.
In that type of door, the brackets serve to fix the door assembly. They are fixed to the wall on the top edges of the opening. Those brackets are usually made of folded sheet metal and by welding. The accuracy of the parts manufactured in that way is limited. When assembling the door, it is often necessary to make adjustments and to re-drill holes, etc. Slideways 5 are disposed on the sides of the opening for receiving and guiding the edges of the curtain while it is moving up and down, and for holding it against the pressure of the wind or of draughts when it is lowered. In Patent EP-0 717 807, the slideways are fixed at their tops to the brackets, and at their bottoms to the floor. Certain other members can be fixed to the brackets by welding or by means of screws and bolts. Such members can serve to carry bearings (e.g. ball or roller bearings), for receiving a motor or a rolling-up shaft. It is possible to fix retention elements to prevent a shaft from falling if one end of it is broken accidentally. Such a retention member is described in Patent EP-0 586 271. Elements also exist that serve to re-insert the edges of the curtain into the slideways if ever they come out therefrom. Those elements can be fixed to the brackets or to side uprights of the door that contain or that constitute the slideways (see Patent EP-0 476 788). Elements also exist that are fixed to the top of the door and that serve to re-center the curtain at the start of lowering so as to ensure that the edges of the curtain are placed properly in the slideways.